Finger for loom dobbies



June 4, 1929. A. A. GORDON FINGER FOR LOOM DOBBIES Filed Jan. 16, 1928 flag/rd? 7 A55? 7- A. Garza/v I? vw/vsys Fatented June 4, 1929.

UNITED -STATES 1,716,047 PATENT OFFICE.

ALBERT A. GORDON, F WORCESTER, MASSACHUSETTS, ASSIGNOR T0 CBOMPTON &; KNOWLES LOOM WORKS, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

FINGER FOR, LOOM DOBBIES.

Application filed January 16, 1928. Serial No. 246,955.

. This invention relates to fingers for loom dobbies and it is the general object of the invention to provide an improved finger made preferably of sheet metal and being of such form that the wearing surface which comes in contact with the dobby pegs may be hardened to render the same more durable than dobby fingers in use at the present time.

1 Loom dobbies employ a plurality of fingers which are located over the pattern chain, each finger being provided on the under side thereof with a groove to receive a dobby peg. The sequence in which the harness frames in the loom are raised and lowered is dependent upon the order in which the dobby fingers are raised and lowered. The dobby fingers are arranged side by side to lie under the pattern mechanism and each finger must be free to move without disturbing its neighbors. For this reason the upper part of the dobby finger is usually made of a thickness somewhat less than the distance between the centers of adjacent dobby fingers to provide clearance.

' It is desirable of course that the under surface of the dobby finger which has sliding engagement with the dobby peg be as broad as possible to present a large wearing surface and also the lower portion of the dobby finger located immediately above the wearing surface should be hardened. It is an important object of my present invention to provide a dobby finger formed preferably of sheet steel having the lower portion thereof pressed out and expanded to a thickness somewhat greater than the thickness of the upper partof the finger to provide a peg run having a broad wearing surface. I find that it is somewhat difficult to case harden the thicker lower portions of the dobby finger without making provision for a penetration of the hardening compound from practically all sides of the dobby run and it is a further object of my invention to reduce the thickness of the upper portion of the dobby finger immediately above the run so as to expose a larger proportion of the peg run to the hardening compound.

I find that the objects set forth herein can be attained by use of a pair of holding members which are forced into the lower portion of the dobby finger to hold the same while a press acts to broaden or expand the bottom of the finger to form the peg run.

With these and other objects in view which will appear as the description proceeds, my lnvention resides in the combination and ar rangement of parts hereinafter described and set forth in the claims. i

In the accompanying drawings wherein I i have shown a convenient embodiment ofmy invention, 1

.Fig. 1 is a diagrammatic view showing a dobby equipped with dobby fingers made accordlng to my presentinvention,

Fig. 2 is a top plan view of a portion of a dobby showing the relation of the dobby fingers Fig. 3 is an enlarged vertical section across one of the dobby fingers taken on'line 3-3 of 1gs. 4, 5 and 6 represent diagrammatically thesuccessive steps in the formation of my improved finger, and

Fig. 7 is a diagrammatic view setting forth certain features of the invention;

A dobby such as my invention may be applied to may include a plurality of ha'rness jacks 10 one of which is shown in Fig. 1 and each jack may be pivotally connected to a dobby back lever 11. The opposite ends of the dobby back lever are pivotally connected to' hooks 12, which cooperate with oppositely reciprocating knives 13. A cylinder 14 carrying pattern chain bars 15 with pegs 16 may be provided to determine the order in which the hooks 12 are raised and lowered. The matter thus far described is of common construction and is given merely .to indicate the manner in which my improvedfinger may be used.

My present inventionrelates to the fingers which are raised and lowered by thepegs 16 and in carrying my invention into effect I provide preferably two forms of fingers F and F, the finger F having an upwardly eX- tending tail 20 which cooperates with one of the lower hooks 12 while the finger F has a substantially horiozntal tail 21 which .acts to raise and lower a rod 22 to control the position of the upper hook. It is to be under stood that each harness jack 10 has associated therewith two hooks 12 andtwo fingers F and F. i I

As shown more particularly in Fig. 3, the upper portion of the finger indicated at 80 is of less thickness than the distance between two adjacent dobby fingers so that said fingers may move without objectionable fricof the finger so as to providea large fwear- 7 ing surface for the pegs. If desired the width of the run 31 may be made almost equal to the distance between two adjacent fingers. a

It is customary to form dobby fingers with relatively narrow up er portions and relatively broad runs am I make no claim for this feature of my fingers but I believe it is new to form the dobby fingers with a portion of reduced thickness between the run and the upper part of the finger. This feature of the invention, as shown in Fig. 3, is brought about by forming each finger with an arcuate groove 33 and having said grooves of such depth that the portion 34 lying therebetween is of substantially less thickness than the upper part30 of the finger. The rooves extend preferably at a uniform distance above the under curved side of the run.

The purpose of forming these grooves is set forth in Fig. 7 where I have shown diagrammatically the relation of the grooves 33 to the peg run 31. As shown in said figure the line CL may be taken as the vertical center line extending through asection of one of the fingers and it will be apparent from Fig. 7 that the bottoms of grooves 33 will be nearerthe center line than the vertical upper walls of the portion 30 of the finger and it will also be apparent that the vertical sides 35 of the run 31 are farther from the center line'than are the parallel walls of the upper portion 3O. By reason of the grooves 33 the hardening compound which in case hardening will be .a cyanide bath can penetrate the run 31 from the concave lower surface 32 and from the vertical walls 35 and also from the lower surfaces 36 of the grooves 33. It is the penetration of the hardening compound through the surfaces 36 of the grooves which enable me to harden practically the whole of the run3l by subjecting the finger to heat treatment for a'less period of time than would be the case if the thickness of the upper portion 30 should extend to the run 31. If, for instance, the heat treatment be carried on a suflicient length of time for the hardening compound to penetrate half the distance between the bottoms of the grooves 33 it will be found that the hardening compound has been able to penetrate the whole mass of the run 31. Under these. conditions the upper portion 30 of the finger would have a soft core due to the fact that said portion 30 is thicker than .the portion 34 between the grooves 33. I i

I find that the method by which the broadened run 31 may be-formed conveniently supplies the grooves As shown in Fig. 4 a piece of sheet steel of-a thickness equal to the upper portion 30 of the finished finger may be held inverted between two clamping members 51 and 52, respectively. Pressure maythen beapplied to said clamps to cause the ribs 53 thereofto approach each other and enter the material 50 to form the grooves 33. While said clamps are still in the position shown in Fig. 5"a compressing and expandin'g die member 54'may' be movedd'ownwardly to expand that portion of the material 50 which lies above the ribs 53 to form the run 31.

- The relation of the fing'ers is shown in F 2 wherein the supporting bar 38 for the right end of the fingers as viewed in Fig. 1 has extending upwardly therefrom spaced pegs 39 which are in alignment with certain of the fingers made shorter than certain other of the fingers which project beyond the pegs 39. This arrangement of the fingers may be substantially the same as shown in my co-p'ending application Serial No. 229,217 and forms nopart of my present invention. It not infrequently happens that after heat treating fiat steel pieces are warped or twisted out of shape. I find that the region of reduced thickness 34 between the run31 and the upper portion 30 lessens the e'fi'ect either of these parts of the finger has on deforming the other part and that as a result there is less warping than would be the case without the grooves 33. j

From the foregoing it will be seen that I have provided'a sheet steel dobby finger having a broadened run for the dobby'pegs above which are formed grooves the effect of which is to permit penetration of the hardening compound into the run so that practically the whole mass of the latter can be hardenedin less time than would be the'case ifsaid grooves were notpresentg a I I Having thus describecl my invention it will be seen that changes and'modific'ations may be made therein by those skilled in the 'art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclo'sed,jbut what I claim is: i

1'. A dobby finger formed of sheet steel and capable of heat treatment; said fingerhaving an upper body portion of given thickness and having along the lower edge'thereo'f a peg run of increased thickness, there being a de y pression fOIlIlGCllIl the dobby. finger between the dobby portion and the peg run'portion, said depression running substantially for the length of the peg run and separating said body portion and peg run portion by a third portion which body portion,

treating agent.

2. A dobby finger is of less thickness than the the depressions rendering the peg run penetrable from above by a heat formed of sheet steel and capable of heat treatment, said finger being formed to have po thicknesses, the greatest run on the under rtions of three difierent thickness being at the K0 the least thickness being immediately above side of the finger and the peg run and the intermediate thickness being at the body portion located above the portion of least thickness, the portion of least thickness which lies above the peg run rendering the latter penetrable from above by a heat treating agent. In testimony whereof fixed my signature.

ALBERT A. GORDON.

I have hereunto at- 

